Method of combustion of liquid fuel



Nov. 12, 1940. E, A. JONES ETAL METHOD OF COMBUSTION 0F LIQUID FUEL 2Sheets-Sheet l jgIL/iNTOR.

Filed May 11, 1938 Nov. 12, 1940. E. A. JONES ETAL METHOD OF COMBUSTIONOF LIQUID FUEL Filed May 11, 1958 2 Sheets-Sheet 2 IN VENTORS.

ATTORNEY.

Patented Nov. 12, 1940 UNITED STATES PATENT OFFICE IVHETHOD F COMBUSTION0F LIQUID FUEL of Wisconsin Application May 11, 1938, Serial No. 207,184

2 Claims.

The present invention relates to improvements in oil burners and methodsof securing complete combustion without pulsation and with a minimum ofexcess air.

One of the objects of the invention is to provide an improved methodofsecuring complete and efficient combustion of fuel oil by means of animproved construction of oil burner for delivering the air relative tothe atomized fuel for 1w combustion.

. Another object of the invention is to provide an improved oil burnercombustion method by means of which air is fed to and across the '1flame at a rate which exceeds the speed of flame w propagation adjacentthe burner head so as to eliminate any fluttering, whiiiiing' orpanting.

Still another object of the invention is to provide a method of securingcombustion with an oil burner wherein the products of combustion have ahigh carbon-dioxide content with a high flame temperature resulting froma relatively small amount of excess air, whereby a high rate of heattransfer from the flame is assured together with maximum efiiciency ofthe heating appliance in which the burner is installed.

Other objects and advantages of the invention will be apparent from thefollowing description and the accompanying drawings in which similarcharacters of reference indicate similar parts throughout the severalviews.

Referring to the several sheets of drawings:

Fig. l is avertical elevational view of an oil burner in partial sectionsusceptibleof performing the improved method;

Fig. 2 is an end-elevational view of the burner head of Fig. 1, takenfrom the left of Fig. 1;

Fig. 3 is a fragmentary horizontal sectional view, taken on the line 3-3of Fig. 1, looking in the direction of the arrows;

Fig. 4 is a vertical sectional view, taken on the plane of the line 44of Fig. 1, looking in the direction of the arrows;

Fig. 5 is a vertical sectional view, taken on the plane of the line 5-5of Fig. 1, looking in the direction of the arrows; and i Fig. 6 is avertical sectional view, taken on the plane of the line 6-6 of Fig. 1,looking in the direction of the arrows.

Referring to Fig. 1, l0 indicates in its entirety 50 an oil burner whichcomprises the usual con:

trols, ignition and safety devices and is shown in connection with ablower housing II which rotatably supports on suitable bearings theimpeller shaft l2 carrying a centrifugal fan rotor l3. Tangentiallyconnected to the blower housing H is a discharge tube l4 which isprovided with openings I5 and it at each end for the attachment of theadditional parts of the burner.

The opening i5 is preferably closed by a cover plate ll comprising acasting having an inwardly extending supporting lug I8 provided with acylindrical bore ii] for receiving the fuel pipe 20.

The fuel pipe may be secured in place by a set screw in the threadedbore H.

ill for the burner head, the two attachment collars being suitablysecured together. The supporting member M is provided with an axiallyextending cylindrical flange 32 surrounding a relatively largecylindrical bore 33 which is adapted to receive an outer tube 34. Thetube 34 is suitably secured in place within said bore.

At its outer or left end (Fig. 1) the outer air tube 34 supports an airsupply head 36 which is provided with an outer cylindrical surface 31adapted to be received in the outer tube 34. The head 36 is secured tothe end of the tube.

The air supply head 36 comprises an annular metal member having an innerdiverging frusto conical aperture 40 which surrounds the spray from thenozzle of the burner. The frusto conical surface 40 may be at an angleof approximately 10 degrees more or less to the axis of the collar 36for the purpose of permitting the air to move outwardly with a spreadingmovement and to prevent the air from piling up at the flame dischargemember 4i which is of conveying frusto-conical formation.

The air supply head 36 is provided with a plurality of rearwardlyextending partially cylindrical flanges 42 located in spaced relation to(see Fig. 4) each of which is located at one side of one of the slots43, for the purpose of directing the air which is discharged from theslots 43 through the slots in a tangential direction. The

flanges 41 separate the space between the outer tube 34 and thecylindrical flanges 42 of the collar 38 into a plurality of-compartments, each of which has a discharge aperture comprising a slot43 extending into the frusto conical bore 48 in a tangential direction.The annular space 48 between the tubes 34 and 45 thus constitutes ,anair supply conduit which has its discharge points at the slots 43 forsupplying air in a tangential and forwardfdirection to the flame outsideof the frusto-conica'l member.

The inner tube 45 fixedly supports the frustoconical middle member 4!with, its tapered flange 52, a circular discharge aperture 53, and acylindrical attachment flange 54. The latter flange is secured to thetube 45 by suitable means (notv nozzle pipe 28 andfor the ignitionelectrodes51, 58. The member 58 also acts-as a partition and is providedwith a gate 59 for controlling the supply of air to the inner tube 45.Member 55 has an' outer substantially cylindrical flange 60 which isadapted to be received in the tube 45. It is also provided with aninwardly extending body flange 6| which supports an axially extendinging 62 having an axially extending bore 63 for receiving the fuel pipe28.

30 Fuel pipe 20 is suitably secured in the bore 63. Thus, the member 58is secured as a unit to the fuel pipe and to the cover plate I! withwhich it may be removed and the cylindrical flange 68 slidably wedgeswithin'the tube 45. The insu- 35 lated electrodes 51 and 5a are suitablyheld in position by boss portions of the flange iii. The fuel supplypipe 20 extends through the partition member 55 into proximity to theelectrodes: 51, 58, the threaded end of the fuel pipe 20 being '40provided with a suitable fuel nozzle 8 i.

The partitionmember 58 is also provided with a segmental. axiallyextending flange 82 defining one side of an opening 83 which is adaptedto be closed by the gate 59. The segmental flange 45 82 is provided witha pair of relatively straight v.55 flat body flange 9| which is slightlythickened at 92 to provide material for the bearing comprising the bore,by means of which the gate 59 is rotatably supported upon the pin 88.The shape of the gate 59 (Fig. 4) is such as to fill the aper- 60 ture83 so as to effect a substantial closure, al-

though the gate is adapted to move freely in the aperture 83 under theinfluence of a spring 93.

Spring 93 .has one. end secured to a pin 94 which passes through thegate 59 and has its 65 other end secured to a lug 95 by means of asimilar pin. Gate 59 has an upwardly extending projecting flange 96which is adapted to engage the flat edge 84 (Fig. 3) of the flange 82.The gate is also provided at its free edge with a 70 cylindrical flange91 extending from the upper edge of the gate and curving down around theperiphery of the gate to a point adjacent the pivot 88'.

. The cylindrical flange 9'I tapers in width from 75 the maximum widthat the upper edge to :zero

adjacent the lug or thickened portion". Thus, I when the gate isslightly opened, the flange 91 -is still adapted to close what wouldotherwise be a crack at the periphery of the gate, but permits anopening only at the upper 'edge of the gate 5 between the flange, 85 andthe edge 84. Thus, when air is discharged through the opening 83,- itmust be discharged upwardly and forwardly and take a spiral coursewithin the tube 45. The opening of the gate disposes its body slightlyin 10 a spiral direction and the aperture formed by opening of the gatedischarges air in that direction. Air is then supplied through the innertube 45 in a spiral and forward direction surrounding the spray anddischarging through the aperture 53 of the frusto-conical member 4|. Theamount of opening of the gate 59 may be regulated by a threadedadjustment rod 28 which is provided with pairs of lock nuts 99, I80,fixedly secured upon the threaded portion illl which is 20 threadedinto' a threaded bore I02 formed in the lug 95. The inner end of the rodis rounded and bears against the gate 59 which may be opened by thepressure of the air or by the action of the rod 26. The nuts 99 and modefine the maximum and minimum opening positions of gate 59 and shouldbe so adjusted.

The operation of the oil burner is as follows: The electrodes 51, 58 maybe energized by any suitable form of continuous or intermittent ignitionand are adapted to ignite the liquid fuel which is atomized and sprayedby the nozzle 8|. Air for combustion is supplied to the spray by theinner tube 45, the air traveling within the tube in a spiral orrotaryforward direction and discharging from the end of the member 45 whichtends to restrict the flow of the air and therefore to accelerate theair at the nozzle opening 53. Additional air is introduced through theslots 43 in a tangential and forward direction and is discharged fromthe tapered opening 49 in such manner as to prevent the air'from pilingup at the frusto-conical member 4|, the additional air being alsointroduced at 'a higher velocity so as to accelerate the flow of oxygento the flame as the flame projects outwardly while it is in combustion.-The velocity of this air jet from the tapered opening 40 is greaterthan the velocity of that portion of the flame which breaks back towardits source, so that the flame is positioned away from the firing head.The surface 48 of the head 36 is provided with spaced-apart aperturesI05 through which air is also discharged to mingle with the air from theslots 43, and the air from these apertures is effective in facilitatingprogressive combustion.

As has been mentioned heretofore, the present invention aims at theattaimnent of relatively perfect combustion with a minimum of excess airand with the provision of a stable flame which is devoid of pulsation.In oil burning devices when theoil is sprayed into a hot chamber,vaporization first takes place, followed by oil cracking bon is releasedin the form of soot. It therefore follows that free hydrogen is presentand is burning in situations where this disassociation occurs.

explained, pulsation is caused by the flame strik-' ing back toward thenozzle and air discharge as the temperature increases, and this resultsin blocking the air supply as expansion occurs within the restrictedarea. This action is followed by momentary smothering and lowering ofthe temperature which causes the flame to recede, permitting areestablishment of the air supply, followed by a continuous repetitionof the first and then the second of these pulsating fire.

There have been many attempts in the prior art to eliminate flamefluttering or panting, but such attempts have not been comparable tothat of the present invention because the prior attempts, of which theU. S. patent to Vollmer No. 2,078,884 and British Patent No. 419,852 of1934 are examples (and which exempliflcations have not been based on aclear understanding of the cause and effect of flame fluttering), haveattempted to overcome the difliculties by a recirculation of theproducts of combustion. In view of these disclosures, the reason for atleast partial elimination of pulsation in the flre when recirculationwas employed, is obvious, since the dilution of the. oxygen in the airsupply by products of combustion containing water and carbon dioxide,

conditions, producing a inert gases, which have replaced results in anmethod is objectionable because it results in heating and fouling of thenozzle, electrodes, and other portions of the equipment. While initiallythis procedure may be effective, it ultimately becomesmore and moredifflcult to obtain complete combustion as the inner portions of theequipment become more and more heated and fouled, and flame volumes willalso be increased and flame temperatures will be reduced by this method.Furthermorethe matter of adjustment becomes very critical.

'I'he'result in the present invention is a high eiiiciency conical flamefrom which panting, whiffling and fluttering is eliminated. Any numberof vanes and slots may be employed, but they are preferably uniformlyarranged around the periphery of the air supply head. In the presentinvention a highly desirable flattened, conical flame is produced, andthe necessary air for supporting combustion is introduced uniformly and'air must come into contact with the burning oil and gases duringcombustion so that it is unnecessary to provide an excessive amount ofair which will tend to reduce the temperature and eillciency in order tosecure clean and complete combustion.

Our improved method of securng efllcient combustion comprises theatomization by spraying of liquid fuel into air which mixture is ignitedand the supply of air adjacent the spray with a forward motion, and theintroduction of additional air at a. higher velocity than the rateofflame propagation, at the root of the flame for the purpose ofeliminating fluttering, whiflling or panting, and effecting smooth anduniform combustion. It will thus be observed that we have, by means ofour improved method and construction of burner, solved the problem ofeliminating fluttering, whiiiiing or panting of the flame with which webelieve the entire 011 industry is and has been for some time concerned.Also in the present invention there is in the products of combustion ahigher percentage of CO: with a smaller amount of excess air than hasbeen possible of attainment heretofore.

What is claimed asthe invention is:

-1. The method of combustion of liquid fuel, which comprises, deliveringa jet of atomized liquid fuel along an axis toward a combustion zone,mixing the atomized fuel with primary air advancing along the axis withthe jet at relatively low velocity and deflecting the outer portions ofsaid primary air inwardly to produce a nebulous mixture proceedingslowly toward said zone, igniting the mixture, and thereafter injectinginwardly into the burning and axially advancing mass of mixtureadditional air moving at higher velocity and sufficient to supportapproxicient to support approximately complete com-- bustion of thefuel. I

' EDWIN A. JONES.

MICHAEL L. LAVORGNA. JOHN C. WES'I'MON'I. SAM C. OLSON.

